Host-parasite-pathogen interactions 

1. Community composition has been shown to alter pathogen dynamics in tick-borne disease systems. This is because some hosts are better reservoirs than others. In California, the western fence lizard is the primary host of western black-legged ticks, yet it is not a reservoir for disease. In my master’s work, I was curious about the impact of different blood meal histories on a tick’s future susceptibility to Borrelia burgdorferi, ie, the Lyme disease pathogen. I found that a history of blood meal significantly alters their susceptibility, or vector competence, to Bb. Counterintuitively, lizards made ticks far more susceptible to Lyme infection in their next life stage. Through transcriptomics, we found that this is likely due to antimicrobial activity initiated during the lizard blood meal. This study shows just how complex disease ecology can be at each research scale!